Another Severe Weather Outbreak Possible (Thursday)

Depending on whether the clouds are thick or thin in the morning could determine whether or not our atmosphere will support tornadic activity. Tomorrow's hodograph looks fairly impressive, considering we live in North Florida. Notice the curved nature to the line. This indicates winds will be twist in the atmosphere.

Forecast for Around Noon

The best timing of the severe weather looks to be from 10 AM - 2:30 PM. The rainfall will end much earlier than it did today, but it could be just as heavy and severe.

Severe Weather Outbreak Possible For First Coast

All the right ingredients seem to be coming together for a severe weather outbreak tomorrow (Wednesday) night. What will be most telling is tomorrow's launch of the weather balloon. The weather balloon will tell us if the atmosphere is charged up enough and if winds are aligning in various layers of the atmosphere. 

Example of Readings from a Weather Balloon.

The Storm Prediction Center has a large portion of Florida and Southern Georgia under a slight risk zone for Wednesday. Any given area within the green zone has about a 15% chance of seeing a damaging storm. What will be most telling is whether the morning starts out cloudy or if we get some substantial daytime heating.

Heavy Storms Surround Area @ 7pm 

Rainfall will average around 1.0 inch across a good part of the area. Severe threats will be hail, strong winds, and tornadoes. The best chance of seeing strong thunderstorms will be from 2:30 PM to 7:45 PM.

EHI levels are at values that are alarming, if sufficient heating exists.  This index combines both CAPE and helicity.  Both are associated with the amount of potential spin in the atmosphere. EHI values will approach 2.5.

 EHI Legend:

>0.5 EHI > 1	Severe Weather Likely Supercell potential
1 to 5	up to F2, F3 tornadoes possible
5+	up to F4, F5 tornadoes possible

More information and fine tuning as it comes in....

Drought Relief on the Way...

Rain is on the way; it's not in the short term forecast, however. The simple problem over the last couple of weeks has been that the NAO (North Atlantic Oscillation) has been positive. The NAO basically represents pressures in and along the Atlantic Basin. When the NAO is positive there is usually a dominant subtropical high and an rather strong North Atlantic/Icelandic low. Because of the strength of both systems, they produce a strong gradient between pressures. Hence, the windy conditions we have experienced over the past couple of weeks.

Depiction of Positive NAO

Under a positive NAO setup, high pressure's influence typically reigns over the area. This equates to weak systems pushing through the Jacksonville area or bypassing the area completely. Examples of this include numerous squall lines this year, and others, falling apart before they reach the area.

Squall line quickly weakens as it enters North Florida.

An interesting statistic to look at it is the number of severe weather reports there are during positive and negative NAO events. The following numbers are for only the Florida peninsula, so far this year. (They do not include areas west of Tallahassee.) 

NAO (Negative): 43
NAO (Positive): 17

What this means is that as the NAO turns negative, we will have to watch for severe weather. Because of the extreme heat, as well as, converging jet streams the percent chance of severe weather will be the at the highest threat levels, so far, this year.

A negative NAO tends to have fewer storms over the North Atlantic and more over its mid sections. The dominate Atlantic high, which protrudes into the Southeast during positive NAO events, weakens and heads eastward. This leaves the Southeast usually vulnerable to an active pattern. This scenario is exactly what is in the pipeline for the last week of March and first week of April.

Negative Phase Setup of the NAO

NAO Turns Drastically Negative

The above picture is of esemble forecast models. They are unamious  that the NAO will turn negative over the next couple of weeks. This means two things: our constantly windy conditions will relax, and a lot of rainfall is on the way.

>GFS Forecast Model: 
Date: 3/28-4/05
Number of Signifcant Storms: 3
Precip.: 3.00 inches of rainfall

Update: Possible Earthquake Near Flagler County?

Just got an email about the Orlando Seismograph... This is the reading from the Seismograph in Orlando:

Notice the large troughs that develop between 10 and 20 minutes after the hour. The shaking of the earth's surface is not from any type of aircraft. An earthquake or a meteor impact is not out of the question, as a possible cause.

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North Florida, Flagler County Rumbles

Numerous residents of St. Johns, Flagler, and Volusia Counties reported feeling and hearing rumbles, at a little after 9 AM, on Friday morning. So, what force caused the commotion? No one knows. It was reported that an military aircraft broke the sound barrier, which caused the earth to rumble. This rumor turned out to be false. NAS Jax and the FAA both say military exercises were not in progress, and there was not even a single plane in the sky, near the affected region.

Could the rumble have been an earthquake? Possibly. The USGS did not record any seismic activity. But one has to remember that the nearest and only seismograph is on the west side of Orlando. This means it is possible that the earthquake recording device could have easily missed the earthquake. The USGS agrees with this plausible scenario.

Another scenario that exists is that a meteor entered earth's atmosphere and plunged into the Atlantic Ocean. Just like the earthquake scenario, we will never know whether the meteor hypothesis is what actually happened or not. A meteor can cause trembles to occur, just like the ones experienced in Florida. One shred of evidence that backs up the meteor theory is the NWS radar, from approx 9:15 AM.

Notice the little, green "speck" to the east of Florida. Could the doppler radar have picked up the meteor or is it simply a false return? (The air was too dry to have showers around.) No observations exist of meteors during the 9:00-9:30 AM time period. It would have been hard to see such an object with the rising the sun. 

It is likley that we may never know the true answer to what caused the earth to rumble, in North Florida, on 3/18/2011.

Computer Models Now Tracking Radiation

Models that are usually used for hurricane forecasts and your everyday weather planners are now being examined for another feature they can show. Models, such as the GFS, can show the future path  that airborne particulates will take. This is particularly helpful, in these times, because of the radiation that is being leaked into the atmosphere from nuclear sites in Japan.

The latest run of the GFS

It is important to know just how far radiation particles are making it up in the atmosphere. So far, no one has a clue. Based off of what the computer model is saying, current particles will not reach Florida in any capacity. If both the quantity and the quality of radiation being released increases, the story could be different.

The GFS lays out three trajectories, indicated by the red, blue, and green lines. None go over the First Coast or even make it close. The lines go out the entire forecasted time of an particle's lifespan. 

>>Check Out the Latest Run of the Computer Model Here

Could Radiation From Japan Reach Jacksonville?

In a complete nuclear meltdown, radiation would reach the First Coast, from Japan. Don't get too concerned about the possibility though. Radiation levels would be significantly less than those seen from x-rays and even kitchen appliances. Locations that would have to take precautionary measures would be those areas west of the Rocky Mountains.

Possible Nuclear Fallout

What both helps and hurts the First Coast is the jet stream or winds in the upper layers of the atmosphere. In the Northern Hemisphere, major wind patterns travel from west to east. They also zigzag and loop around, similar to a roller coaster track. This sloped path gives the radiational particles enough time and space to dissipate. The Rocky Mountains would basically serve as a divider between the questionable zone, to the west, and the no threat zone, to the east.   

Jet Stream Pattern

Once again, the threat to the United States would only happen in a full blown nuclear meltdown and catastrophe.

>>Monitor LIVE Radiation Levels in Tokyo...Click Here

>>LIVE Cam at Fukushima Daiichi Nuclear Plant

Jacksonville's Earthquake History

With events in the Pacific realm, it is interesting to look at North Florida's and South Georgia's  earthquake history. Although our area is not usually considered to be a state subject to earthquakes, several minor shocks have occurred here. Damaged has occurred because of these rumbles.

> A shock occurred near St. Augustine, in the northeast part of the State, in January 1879. The Nation's oldest permanent settlement, founded by Spain in 1565, reported that heavy shaking knocked plaster from walls and articles from shelves. Similar effects were noted at Daytona Beach, 50 miles south. At Tampa, the southernmost point of the felt area, the trembling was preceded by a rumbling sound at 11:30 p.m. Two shocks were reported in other areas, at 11:45 p.m. and 11:55 p.m. The tremor was felt through north and central Florida, and at Savannah, Georgia.

> In January 1880, Cuba was the center of two strong earthquakes that sent severe shock waves through the town of Key West, Florida. The tremors occurred at 11 p.m. on January 22 and at 4 a.m. on the 23rd. At Buelta Abajo and San Christobal, Cuba, many buildings were thrown down and some people were killed.
 
> The next tremor to be felt by Floridians also centered outside the State. It was the famous Charleston, South Carolina, shock in August 1886. The shock was felt throughout northern Florida, ringing church bells at St. Augustine and severely jolting other towns along that section of Florida's east coast. Jacksonville residents felt many of the strong aftershocks that occurred in September, October, and November 1886.

> On June 20, 1893, Jacksonville experienced another slight shock, apparently local, that lasted about 10 seconds.

> Another minor earthquake shook Jacksonville at 11:15 a.m., October 31, 1900. It caused no damage.

> A sudden jar caused doors and windows to rattle at Captiva in November 1948. The apparent earthquake was accompanied by sounds like distant heavy explosions. Captiva is located on Captiva Island, in the Gulf west of Fort Myers.

> On November 18, 1952, a slight tremor was felt by many at Quincy, a small town about 20 miles northwest of Tallahassee. Windows and doors rattled, but no serious effects were noted. One source notes, "The shock interfered with writing of a parking ticket."

> On July 3, 1992, at 11:30 p.m., a giant tidal wave estimated to be 18 ft. high crashed on Daytona Beach, causing 75 minor injuries and crushing cars parked on the beach. Though its origin was claimed to be a weather squall, there is no way to prove it was not a distant shift in the earth.

> On October 24, 1997, the Panhandle of Florida was rocked by earth tremors. Supposedly, it originated in central Alabama.

> The last tremor to shake our city occurred in 2003. The ground shook in Jacksonville after a earthquake in Northeast Alabama tipped the Richter Scale at 4.9. Its ground tremoring rattle reached as far Northeast as North Carolina.

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Severe Weather Threat Possible For North Florida

Severe weather is possible tomorrow night (Wednesday Night thru Thursday Morning). There is a possibility of two lines of severe weather. The first line will contain the strongest storms. The second line will provide the heaviest rainfall.

The first storms should pop up around the area from 8:30-10:30 PM. The second line could resemble more of a bow echo line. (Bow echo lines are associated with straight line winds) Rainfall totals will vary greatly across the area. An average of .50 inches of rain is a good bet. Locations that find themselves under severe thunderstorms could pick up 2+ inches of rain in a short time period.

The area that will be most susceptible to supercells will range from eastern Texas to South Carolina. Southern Georgia and areas west of Lake City are included in this high risk area.

There are several reasons why there could be SEVERE thunderstorms in the area:

First: Dew points will be on the high side, for this time of year. (Dew points likely around 65 degrees.)

Second: Temperatures from 70-74 degrees.

Third: Precipitable water content  will be 1.25 to 1.75 inches (moderate moisture content). P.W. is the amount of moisture that exists in the complete vertical column, above our heads.

****What has me most concerned: EHI Values will be from 1-1.98. This index combines both CAPE and helicity.  Both are associated with the amount of potential spin in the atmosphere.

 EHI Legend:

>0.5 EHI > 1	Severe Weather Likely Supercell potential
1 to 5	up to F2, F3 tornadoes possible
5+	up to F4, F5 tornadoes possible

What should provide better answers on whether severe weather will be possible is the launch of the a weather balloon, tomorrow morning, around 7:30 AM.

This is what New Orleans looked like earlier today (they saw numerous tornadoes nearby):

Last Chance to See Discovery in Space

Tomorrow Night will be the last night to see Discovery float, above eyes, in the sky. Discovery is set to land during the afternoon hours on Wednesday. If weather prevents a landing, then Wednesday night will also provide a night to see the space shuttle. Make sure to look NNE Tuesday night. Don't blink either because the space shuttle will be only visible for about 60 seconds. Skies in North Florida and South Georgia look good for viewing.

Major Severe Weather Outbreak Sunday 3/6

Continuing to watch an impressive storm system for the First Coast. Its wrath will be felt on Sunday. Strong winds look like the main concern with the thunderstorms. Can't rule out tornadic activity nearby. The Storm Prediction Center is missing the ball, with this storm, as it pertains to the First Coast. Officially, we are only in a designated 5% zone for severe weather. The likelihood for severe weather should be around 15%-25%. The best chance of rain is from just after the noon hour to around sunset. Rainfall amounts will total around one inch, across the entire area.


There are several reasons why I am calling for SEVERE thunderstorms:

First: Dew points will be on the high side, for this time of year. (Dew points likely around 65 degrees.)

Sunday Dew Points

Second: Temperatures from 75-80 degrees.

Sunday Temperature

Third: Precipitable water content  will be 1.25 to 1.75 inches (moderate moisture content). P.W. is the amount of moisture that exists in the complete vertical column, above our heads.

Precipitable Water Content

Four: EHI Values will be from 0.3-0.8. This index combines both CAPE and helicity.  Both are asociated with the amount of potential spin in the atmospehere.

EHI

>0.5 EHI > 1	Severe Weather Likely Supercell potential
1 to 5	up to F2, F3 tornadoes possible
5+	up to F4, F5 tornadoes possible

Jacksonville Winter Weather Summary 2010-2011

            For the second consecutive winter, long-lasting cold temperatures and multiple hard-freeze events headlined the weather across all of Southeast Georgia and Northeast Florida.  Climate locations averaged twice as many the normal number of freeze events from December to February.  Winter began with strong negative phases of both the Arctic Oscillation (AO) and North Atlantic Oscillation (NAO). These phases help funnel cold-air outbreaks down through the Eastern United States where they settle over the Deep South for long periods of time.

The strong La Nina event ongoing over the Pacific Ocean did help continue below normal precipitation amounts from the autumn of 2010, especially in December and the latter half of February.  The first 6 weeks of 2011 were quite cool and wet across portions of northeast Florida where total winter precipitation amounts averaged close to normal.  Areas across southeast Georgia averaged closer to 5 inches below normal for the winter months

Freezes
The total number of freeze events between December 2010 to February 2011 set all-time records at local climate sites (Table 1). Alma, Georgia dropped at or below freezing for an all-time record 43 times this past winter, which broke the old record of 42 times set during the winter of 1963-64.  Across northeast Florida, Jacksonville recorded a total of 30 freeze events this winter season while Gainesville recorded 27. These totals rank the winter of 2010-2011 as having the 2^nd most freeze events for both Jacksonville and Gainesville.  In fact, the month of December was the coldest on record at Alma, Jacksonville and Gainesville.  December 2010 ranked as the third coldest for St. Simons Island.

Climate Site	Winter 2010-11 Total Number of Freezes	Normal Winter Number of Freezes (Dec-Feb)	Current and Old Record Number of Freezes
Jacksonville, FL	30 (Rank 2nd all-time)	16	31 in 1976/77

Temperatures

Temperatures finally started to moderate during the last half of February which was the only month this past winter to have above normal temperatures.  Even with the mild February, all of the climate sites registered one of the coldest winters on record, with average winter temperatures ranging from 2 to 6 degrees below normal.  In fact, all of the climate sites reported one of the coldest winters on record.  Jacksonville, Florida had back-to-back record setting cold winters during 2009-2010 and 2010-2011 which both ranked in the Top 5 all-time coldest winters.  The winter of 2010-2011 ranked just slightly colder than last winter.

Climate Site		December 2010 (All-time Coldest Rank)	January 2011      (All-time Coldest Rank)	February 2011    (All-time Warmest Rank)	Winter2010/11 Total (All-time Coldest Rank)
Jacksonville, FL	Normal Temp Actual Temp Departure	55.0F 46.1F -8.9F (1st)	53.1F 49.0F -4.1F (13th)	55.8F 58.5F +2.7F (47th)	54.6F 51.0F -3.6F (4th)

Precipitation

December of 2010 was not only one of the coldest on record, but it was also a very dry one which felt drought conditions that escalated last autumn.  Most climate sites received less than an inch of precipitation and ranked as one of the Top 10 driest Decembers on record.  At the beginning of 2011, the storm pattern shifted which brought a series of low pressure systems from the Gulf of Mexico across the Florida Peninsula.  These storms yielded much needed rainfall, and those across northeast Florida received normal to above normal rainfall totals.  Southeast Georgia, which was on the weaker side of these precipitation-producing systems, received less rainfall.  This continued severe drought conditions as precipitation values remained below normal

Climate Site	Precipitation        in Inches	December 2010 (All-time Driest Rank)	January 2011	February 2011	Winter2010/11 Total (All-time Driest Rank)
Jacksonville, FL	Normal Pcpn Actual Pcpn Departure	2.64” 0.34” -2.30” (9th)	3.69” 5.75” +2.06”	3.15” 4.06” +0.91”	9.48” 10.15” +0.67

Freezing Precipitation Events
As a low center tracked across the Florida peninsula on January 10^th, cold air combined with enough moisture to produce light freezing rain along the Altamaha River Basin.  The freezing rain coated some of the trees in the region but did not cause any transportation problems. Some light snow flurries were also reported in the wake of a cold low pressure system on December 26^th, 2010, across southeast Georgia and portions of northeast Florida along the I-10 corridor.  The Jacksonville metro area even experienced a brief period of snow flurries that morning.

What TV Station Has The Most Accurate Weather?

WTEV (CBS 47 & Fox 30) had the most accurate weather forecasts, during the month of February. They swept competitors WTLV (NBC 12 & ABC 25) and WJXT, in nearly every category. The only other notable fact is that if you were only interested in the 24 hour forecast. WTEV and WTLV tied in their correctness for the 24 hour weather forecast.  

Overall winner for the month of February (The Most Accurate weather Forecast):
1. WTEV
2. WTLV
3. WJXT

Most accurate 24 hour forecast
1.TIE: WTEV & WTLV
3. WJXT

Most accurate 48 hour forecast
1. WTEV
2. WTLV
3. WJXT

Most accurate 72 hour forecast
1. WTEV
2. WTLV
3. WJXT


Most accurate 96 hour forecast
1. WTEV
2. WTLV
3. WJXT


Most accurate 120 hour forecast
1. WTEV
2. WJXT
3. WTLV